防火性能式設計法應用於電影院與挑高中庭之建築物

Abstract

在國內現行的消防相關法規中，主要以規格式法規為主，對於空間較特殊的建築物，例如體育場、電影院或是挑高中庭，使用傳統法規條文並無法確實的達到防火安全的目的，故需以性能式設計之方法來確保其消防設備的性能能夠確實的達到保障人員安全的目標。 本研究共分析兩個案例，案例一為具有挑高中庭空間之商場百貨，案例二為電影院，利用性能式設計法（performance-based design method）之驗證程序和步驟，以及數值模擬軟體FDS（Fire Dynamics Simulator）與SIMULEX進行煙控系統設計分析與避難性能評估。在案例ㄧ中分別改變火源位置以及排煙設備的風量，探討挑高中庭空間發生火災時的煙流情形，並且觀察中庭部分的防火捲門是否有可能因為關閉時使人員困在裡面，造成人員生命安全的危害。在案例二，此案例中主要改火源位置以及排煙口的位置，來探討不同的相對位置對於煙流的控制是否有影響。在分析過程中，首先以火災模擬軟體FDS模擬火災的煙層流動情形、CO濃度分佈、溫度分佈、能見度分佈以及煙層降至1.8m之時間來計算出所能提供人員疏散的時間。接著再利用動態避難模擬SIMULEX模擬計算人員避難逃生情形和避難所需時間，以評估人員避難安全。經由模擬結果可得知兩個案例的煙控系統設計，均滿足人員生命安全的標準。並且於案例二中發現，在電影院空間中，煙層下降的高度會因為火源位置的高度而受到限制，當火源位置越高時，煙層會被侷限在天花板的區域累積；反之，當火源位置越低，則煙層便會迅速下降至觀眾席區域，造成人員避難上的危害。

In Taiwan, the present fire safety code is focus on “prescribed” one. For some special buildings, like gyms, movie theaters and atrium buildings, they are very hard to comply with the standard fire safety code. To solve the difficulty, it needs to apply the”performance-based design method” to ensure the performance of fireproof equipments to maintain the goal of occupant safety. This research analyzes and evaluates the performance of smoke control system designs and the occupant egress, respectively, by utilizing the verification procedures of performance-based design method and the numerical simulation software, FDS (Fire Dynamics Simulator) and SIMULEX. The content of this research consists of two cases, which case 1 is an atrium building and case 2 is a movie theater. In case 1, the fire locations and the velocities of exhaust fan are changed to analyze whether the resultant smoke movement (including visibility effect), CO concentration, temperature distribution are harmful to the occupants in egress. It also analyzes the evacuation results when occupants inside the atrium building are subjected to a worst scenario that the rolling fire door, activated by an alarm signal, reaches the floor to close the region. In case 2, the locations of designed fires and vents are changed to analyze and evaluate whether the resultant hazardous conditions affect the audience inside the theater. At first, FDS is used to simulate the fire scenario to obtain smoke movement, CO concentration and temperature distributions and visibility. After that, a dynamic computer model, SIMULEX, is applied to calculate of the conditions of evacuative occupants and the available evacuation time to justify the safety level of egress. From the simulation results, all the two cases are found to be able to comply with the safety requirements for occupant evacuation. In addition, this research discusses the influence of the smoke height in case 2. The smoke layer depth will be restricted by the height of fire location. When the fire is located at a higher position, the smoke will only fill up the ceiling. On the contrary, when the fire is located at a lower place, the smoke will fully fill up the movie theater that threaten the safety of evacuating people.